Factors Associated with the Occurrence of Epistaxis in Natural Canine Leishmaniasis (Leishmania infantum)

Treatment and Healing of Leishmaniasis in a Wolf in Semi-Captivity Regime from an Educational Center of Zamora Province (Spain)

Leishmaniasis in wild canids is a vector-borne disease caused in Europe by the protozoan parasite Leishmania infantum. To date, there is limited information on clinical signs and laboratory abnormalities in wolves due to leishmaniasis. The current clinical case report described a female Iberian wolf (Canis lupus signatus) housed in semi-captivity conditions at the Centro del Lobo Ibérico "Félix Rodríguez de la Fuente", in Robledo de Sanabria, Zamora (Spain), with an interdigital ulcerous wound at the right forepaw, hyper-gammaglobulinemia, and abnormal liver blood parameters. Definitive serodiagnosis of leishmaniasis was established using antileishmanial serum antibodies and PCR analysis of different biological samples. A gold-standard anti-L. infantum treatment protocol consisting in subcutaneous meglumine antimoniate and oral allopurinol combination was installed. However, the presence of pain at the site of injection due to meglumine antimoniate administration forced its substitution by oral miltefosine. A progressive reduction of the levels of anti-L. infantum serum antibodies and the concentrations of gamma-globulin fraction was detected after antileishmanial treatment as well as a decline of liver GPT. To our knowledge, this is the first case of leishmaniasis diagnosed in a wolf housed in semi-captivity conditions, with the condition subsequently treated and successfully cured.

Elucidating the role played by bone marrow in visceral leishmaniasis

Leishmaniasis is a widespread group of infectious diseases that significantly impact global health. Despite high prevalence, leishmaniasis often receives inadequate attention in the prioritization of measures targeting tropical diseases. The causative agents of leishmaniasis are protozoan parasites of the Leishmania genus, which give rise to a diverse range of clinical manifestations, including cutaneous and visceral forms. Visceral leishmaniasis (VL), the most severe form, can be life-threatening if left untreated. Parasites can spread systemically within the body, infecting a range of organs, such as the liver, spleen, bone marrow and lymph nodes. Natural reservoirs for these protozoa include rodents, dogs, foxes, jackals, and wolves, with dogs serving as the primary urban reservoir for Leishmania infantum. Dogs exhibit clinical and pathological similarities to human VL and are valuable models for studying disease progression. Both human and canine VL provoke clinical symptoms, such as organ enlargement, fever, weight loss and abnormal gamma globulin levels. Hematologic abnormalities have also been observed, including anemia, leukopenia with lymphocytosis, neutropenia, and thrombocytopenia. Studies in dogs have linked these hematologic changes in peripheral blood to alterations in the bone marrow. Mouse models of VL have also contributed significantly to our understanding of the mechanisms underlying these hematologic and bone marrow abnormalities. This review consolidates information on hematological and immunological changes in the bone marrow of humans, dogs, and mice infected with Leishmania species causing VL. It includes findings on the role of bone marrow as a source of parasite persistence in internal organs and VL development. Highlighting gaps in current knowledge, the review emphasizes the need for future research to enhance our understanding of VL and identify potential targets for novel diagnostic and therapeutic approaches.

Immunopathological investigation of a gerbil model of cutaneous leishmaniasis

Leishmaniasis, caused by Leishmania species (intracellular protozoans), is a chronic, systemic disease that causes skin (cutaneous) and internal organ infections (visceral). Its prevalence has increased in recent years. Leishmania species are considered important pathogens that affect public health. After infecting an individual, the pathogen disrupts the immune system, but, there are not enough studies on which immune mechanisms are affected. The aim of this study was to establish a Leishmania major infection model (the causative agent of cutaneous leishmaniasis) in gerbils (Meriones unguiculatus) and to investigate the immune response in this model by examining the expression of important inflammatory genes (IL-1β, IL-2, IL-6, IFN-ɣ and TNF-α). The presence of parasites was confirmed by microscopic examination of samples taken from the lesions and culture studies. The expression of inflammatory cytokine genes was significantly increased in infected gerbils. The changes indicated that both the Th1 and Th2 pathways are activated in cutaneous leishmaniasis infection. Hence, different immunopathological mechanisms should be evaluated in the pathogenesis of the disease.

Signalment, Immunological and Parasitological Status and Clinicopathological Findings of Leishmania-Seropositive Apparently Healthy Dogs

Canine leishmaniosis caused by Leishmania infantum is a disease with a wide range of clinical manifestations. Epidemiological serosurveys performed in Europe often lack a thorough assessment of clinical health status of studied dogs. The aim of this study was to evaluate signalment, immunological and parasitological status and clinicopathological findings of L. infantum-seropositive apparently healthy dogs (n = 212) living in endemic areas. Routine laboratory tests, endpoint in-house ELISA to quantify the anti-Leishmania antibodies, blood Leishmania qPCR and IFN-γ ELISA were performed. All dogs enrolled were L. infantum-seropositive and were classified as healthy (n = 105) or sick (n = 107) according to LeishVet guidelines. The sick group presented a higher proportion of medium to high antibody levels and positive qPCR and lower IFN-γ concentration compared to the healthy group. Sick dogs were mostly classified in LeishVet stage IIa. Biochemical alterations (98%) were the most common clinicopathological findings, with fewer urinary tract (46%) and hematological (40%) alterations. Apparently healthy L. infantum-seropositive dogs can be classified between truly healthy dogs and sick dogs with clinicopathological findings. Sick dogs presented medium to high seropositivity and parasitemia and low IFN-γ concentrations, and their most common clinicopathological abnormalities were serum protein alterations followed by proteinuria and lymphopenia.

First Report of Autochthonous Canine Leishmaniasis in Hong Kong

Canine leishmaniasis is a zoonotic disease caused by Leishmania infantum; transmitted by the bite of phlebotomine sand flies. Leishmania infantum amastigotes were identified by cytology from a locally born Hong Kong dog exhibiting nasal, cutaneous, and systemic disease who was part of a kennel of eight dogs. All eight kennel dogs were subsequently tested serologically by enzyme-linked immunosorbent assay (ELISA) and by polymerase chain reaction (PCR) followed by DNA sequencing for L. infantum infection. The local dog was seropositive and blood and splenic tissue were PCR positive for L. infantum whilst the other kennel dogs were negative on serology and PCR. Autochthonous transmission was suspected for the local dog as Hong Kong lacks known vectors of L. infantum. Either vertical transmission from the deceased dam who had previously died with disease suspicious for leishmaniasis or horizontal transmission from a second non-locally born kennel dog who had been diagnosed previously with leishmaniasis was possible. This is the first recorded autochthonous case of canine leishmaniasis in Hong Kong. Leishmaniasis should be considered as a differential for cutaneous or systemic illness in local untraveled dogs in Hong Kong. In addition, as dogs serve as L. infantum reservoirs for human infection attention should be paid to the possibility of leishmaniasis emerging in Hong Kong.

Canine leishmaniasis in Northern California-A case report

A 3-year-old dog was referred to the Veterinary Medical Teaching Hospital of the University of California-Davis for further evaluation of episodes of epistaxis of 1-year duration and peripheral lymphadenopathy. The patient had a history of atopic dermatitis with no travel history outside of California. Hyperglobulinemia with a polyclonal gammopathy was noted on serum protein electrophoresis. Microscopic evaluation of a bone marrow aspirate sample revealed many free and intra-cellular amastigotes of Leishmania sp. that was further confirmed by qPCR as L infantum. This is, to the best of our knowledge, the first reported case of canine leishmaniasis in the state of California. The patient is believed to have been vertically infected from the dam who is from Serbia and remained subclinical until presentation. Because the clinical progression of leishmaniasis is variable, it is important that precautions be discussed with owners acquiring puppies with dams from endemic regions of leishmaniasis to prevent zoonotic exposure in states where competent vectors are present.

Feline leishmaniosis: diagnosis, treatment and outcome in 16 cats

OBJECTIVES

Leishmaniosis is a vector-borne disease and in European countries is caused by Leishmania infantum. Cats are considered secondary reservoirs of the infection in endemic areas. The objective of this retrospective study is to describe the clinical findings, diagnosis, treatment and outcome of feline leishmaniosis (FeL) in 16 cats in Spain.

METHODS

Medical records of cats diagnosed with leishmaniosis were retrospectively reviewed for cases that met the following inclusion criteria: identification of Leishmania organisms and/or DNA on cytological and/or histological specimens and/or a high anti-Leishmania antibody titre, compatible clinical findings and pathological abnormalities.

RESULTS

Sixteen cats met the inclusion criteria, all of which were living in areas endemic for canine leishmaniosis. Systemic signs were present in 11 cases (68.8%). The most common clinical signs on presentation included cutaneous lesions in 12 cats (75%), ocular disease in six cats (37.5%) and anorexia in six cats (37.5%). A polyclonal gammopathy was noted in 12 cats (85.7%). Non-regenerative anaemia and renal abnormalities were present in six (37.5%) and five patients (31.3%), respectively. In nine cats (56.3%), immunosuppressive conditions/comorbidities were identified. The diagnosis was made in eight of the cats (50%) by cytology, but a combination of diagnostic tests was needed for definitive diagnosis in the remaining patients. Twelve cats (75%) were treated specifically for leishmaniosis. Five of the 12 cats (41.7%) did not improve with treatment. The median survival time in the group of patients treated specifically for leishmaniosis was 17 months. Median survival of patients treated with concomitant diseases was 13 months vs 41 months in those without, although this was not statistically significant (P = 0.557).

CONCLUSIONS AND RELEVANCE

Presentation of FeL appears to be similar to canine leishmaniosis but with some specific features: ulcerative and nodular skin lesions are the predominant cutaneous signs; cats with immunosuppressive conditions or coexisting diseases were more commonly present than typically seen in dogs (mainly feline immunodeficiency virus). A combination of diagnostic tests may be needed for definitive diagnosis.

Evaluation of serum symmetric dimethylarginine as a biomarker of kidney disease in canine leishmaniosis due to Leishmania infantum

Canine leishmaniosis (CanL)-associated chronic kidney disease is a leading cause of morbidity and mortality in Mediterranean countries. Novel renal biomarkers, such as serum symmetric dimethylarginine (sSDMA), may be useful surrogates for the detection of renal functional impairment. The objectives of this study were to investigate sSDMA concentrations in dogs with CanL, with and without azotemia, and to establish any potential association with the prevalence and severity of proteinuria, with the prevalence of decreased urine specific gravity and with the LeishVet clinical stages of CanL. Serum samples from 68 dogs with CanL (50 nonazotemic and 18 azotemic) and 17 healthy dogs were retrospectively examined. Increased sSDMA was documented in 26 % of dogs with CanL without azotemia and in 83.3 % of dogs with azotemia. Serum SDMA was significantly higher in azotemic compared to nonazotemic dogs and was associated with the presence and severity of proteinuria, the decreased urine specific gravity and the advanced clinical stages of CanL. The results of the present study indicate that sSDMA may be a useful adjunct to serum creatinine and urine protein/creatinine ratio for the detection of CanL-associated nephropathy, but it is of limited value for distinguishing among the LeishVet clinical stages of CanL.

Circulating and bone marrow myeloid cells containing Leishmania amastigotes in a case of advanced canine leishmaniosis

A 5-y-old male Poodle mix was presented with intermittent vomiting, anorexia, and weight loss. Physical examination revealed emaciation, lethargy, dehydration, hypothermia, respiratory distress, and splenomegaly. Based on clinicopathologic, serologic, and parasitologic findings, diagnoses of severe leishmaniosis and dirofilariasis were made. Extracellular, intraneutrophilic, and intramonocytic Leishmania amastigotes were observed on blood smear and buffy coat smear examination. In blood smears, 0.2% of neutrophils were observed to be infected; in buffy coat smears, 0.5% of neutrophils and 0.1% of monocytes were found to be infected. Leishmania amastigotes were also found engulfed by eosinophils and neutrophil precursors in bone marrow aspiration cytology. The detection of Leishmania amastigotes in blood smears is rare, and the clinical significance is uncertain. In circulating blood, Leishmania amastigotes are primarily found phagocytized by neutrophils. Although debatable, there is growing evidence that neutrophils are used as carriers enabling the "silent entry" of the protozoa into macrophages ("Trojan horse" theory). To date, cytologic screening of blood smears for the diagnosis of canine leishmaniosis is not a routine practice. Clinical pathologists and practitioners should be aware that Leishmania amastigotes may be present in neutrophils and less frequently monocytes during blood smear evaluation; neutrophil precursors and eosinophils may also be parasitized in bone marrow specimens.

Biomarkers Associated With Leishmania infantum Exposure, Infection, and Disease in Dogs

Canine leishmaniosis (CanL) is a vector-borne disease caused by the protozoan Leishmania (Leishmania) infantum species [syn. L. (L.) infantum chagasi species in the Americas] which is transmitted by the bite of a female phlebotomine sand fly. This parasitosis is endemic and affect millions of dogs in Asia, the Americas and the Mediterranean basin. Domestic dogs are the main hosts and the main reservoir hosts for human zoonotic leishmaniosis. The outcome of infection is a consequence of intricate interactions between the protozoan and the immunological and genetic background of the host. Clinical manifestations can range from subclinical infection to very severe disease. Early detection of infected dogs, their close surveillance and treatment are essential to control the dissemination of the parasite among other dogs, being also a pivotal element for the control of human zoonotic leishmaniosis. Hence, the identification of biomarkers for the confirmation of Leishmania infection, disease and determination of an appropriate treatment would represent an important tool to assist clinicians in diagnosis, monitoring and in giving a realistic prognosis to subclinical infected and sick dogs. Here, we review the recent advances in the identification of Leishmania infantum biomarkers, focusing on those related to parasite exposure, susceptibility to infection and disease development. Markers related to the pathogenesis of the disease and to monitoring the evolution of leishmaniosis and treatment outcome are also summarized. Data emphasizes the complexity of parasite-host interactions and that a single biomarker cannot be used alone for CanL diagnosis or prognosis. Nevertheless, results are encouraging and future research to explore the potential clinical application of biomarkers is warranted.

Renal dialysis and long-term treatment of a dog with kidney disease associated with canine leishmaniosis

Background

Renal disease is considered the main cause of natural mortality in dogs with canine leishmaniosis. The pathological mechanisms associated with kidney injury in canine leishmaniosis include immune complex glomerulonephritis, tubulointerstitial nephritis and occasionally renal amyloidosis. Proteinuria is a frequent finding in canine leishmaniosis and its quantification by the urine protein-creatinine ratio (UPC) is an important parameter in the staging of canine lesihmaniosis as presented by the LeishVet group.

Results

A 4.5 year-old spayed female Belgian Malinois dog was presented to the Hebrew University Veterinary Teaching hospital with epistaxis and rhinitis and diagnosed also with proteinuria and acute kidney injury (AKI IRIS grade V) associated with canine leishmaniosis that developed to LeishVet stage III with chronic kidney disease (CKD) after stabilization. Clinicopathologic abnormalities included azotemia with a peak creatinine concentration of 7.76 mg/dl (reference interval, 0.3–1.2 ng/dl), hypoalbuminemia (1.76 g/dl, reference interval 3-4.4 g/dl), hyperglobulinemia (4.54 g/dl, reference interval 1.8–3.9 g/dl) and proteinuria (urine protein/creatinine ratio 15.6, normal < 0.2). Serology by the enzyme-linked immunosorbent assay (ELISA) for Leishmania infantum was positive with high antibody levels. The dog was hospitalized and treated with intermittent hemodialysis, feeding through an esophageal feeding tube, medical treatment for protein losing nephropathy and antileishmanial treatment with allopurinol. Kidney function gradually improved and the dog’s creatinine levels and proteinuria decreased until complete normalization two years after the acute insult. However, rhinitis and sneezing persisted and although the anti-leishmanial antibodies decreased over time, the dog remains constantly seropositive.

Conclusions

To our knowledge, this is the first report of hemodialysis management of AKI associated with canine leishmaniosis. Hemodialysis was imperative in stabilizing the dog’s renal disease and controlling its azotemia. It demostrates that hemodialysis can be beneficial in the management of acute deterioration of kidney disease in canine leishmaniosis.

Electronic supplementary material

The online version of this article (10.1186/s13071-018-2719-6) contains supplementary material, which is available to authorized users.

Treatment of canine leishmaniasis with marbofloxacin in dogs with renal disease

Treatment of canine leishmaniasis (CanL) represents a challenge. Due to the high prevalence of renal disease associated to CanL, it is important to find an effective drug that does not damage the kidneys. Marbofloxacin has been shown to be effective and well tolerated in non-azotemic dogs with leishmaniasis. To evaluate the safety and efficacy of marbofloxacin in dogs with leishmaniasis and decreased renal function, 28 dogs suffering from leishmaniasis and chronic kidney disease (CKD) were treated with oral marbofloxacin at 2 mg/Kg/day for 28 days. During treatment dogs were assessed by performing weekly physical exams, measuring blood pressure and evaluating blood and urine parameters. Lymph node aspirations were also obtained at days 0 and 28. The global clinical score decreased significantly, from 6.2±3.4 to 4.7±3.1 (p = 0.0001), after treatment. Marbofloxacin also decreased parasitic load in 72% of the dogs. No significant differences in plasma creatinine, urine specific gravity, urinary concentrations of cystatin C, ferritin and urinary protein loss were detected during treatment. A transient but significant decrease in blood pressure was detected up to day 14 (from 180.1±36.6 to 166.0±32.7 mmHg; p = 0.016). Moreover, dogs showed a significant increase in plasma albumin concentration (from 15.0±5.2 to 16.6±3.9 g/L; p = 0.014) and a significant decrease in globulin concentration (from 59.0±18.1 to 54.1±18.0 g/L; p = 0.005). The results demonstrate that, in addition to being effective for treatment of CanL, marbofloxacin is a very safe drug in dogs with CKD and leishmaniasis.

Neurological manifestations in dogs naturally infected by Leishmania infantum: descriptions of 10 cases and a review of the literature

In order to evaluate possible nervous system involvement in canine leishmaniasis, retrospective evaluation of all medical records of leishmaniotic dogs exhibiting neurological signs referred to our hospital over a 5-year period was performed. The records of 10 dogs were reviewed. Depending on the neuroanatomical localisation, the dogs underwent advanced diagnostic imaging, cerebrospinal fluid analysis, electrodiagnostic testing and histopathologic evaluations. The final neurological diagnosis was: meningoencephalitis (n=2), brain haemorrhagic stroke (n=1), haemorrhagic choroiditis (n=1), meningomyelitis (n=2), ischaemic myelopathy (n=1), polymyositis (n=2) and peripheral neuropathy (n=1). This study confirms that both central and peripheral nervous systems can be affected by leishmaniasis and provides an overview on the possible etiopathogenetic mechanisms. In addition, clinical and diagnostic findings, therapy and follow-up of affected dogs are described.

Canine pancytopoenia in a Mediterranean region: a retrospective study of 119 cases (2005 to 2013)

OBJECTIVES

To further clarify the causes of pancytopoenia and to investigate whether underlying cause or severity were associated with survival in an area endemic for vector-borne pathogens.

METHODS

Retrospective review of medical records of 119 dogs with and 238 dogs without pancytopoenia.

RESULTS

Mixed-breed dogs and dogs younger than one year had higher odds of being pancytopoenic. The most common diagnoses included monocytic ehrlichiosis (n=42), leishmaniasis (n=28) and parvoviral enteritis (n=19). The mean white blood cell counts were lower in dogs with ehrlichiosis and parvoviral enteritis compared to dogs with leishmaniasis, while platelet counts were lower in ehrlichiosis compared to leishmaniasis or parvoviral enteritis. Total protein concentrations were lower in dogs with parvoviral enteritis compared to ehrlichiosis and leishmaniasis. Higher haematocrit, platelet and white cell counts were associated with better odds of survival.

CLINICAL SIGNIFICANCE

Infectious diseases appear to be the leading causes of canine pancytopoenia in endemic areas; severe leukopoenia (ehrlichiosis, parvoviral enteritis), thrombocytopoenia (ehrlichiosis) and hypoproteinaemia (parvoviral enteritis), represented potentially useful disease-specific diagnostic determinants. The severity of pancytopoenia significantly affects the clinical outcome.

Insights on adaptive and innate immunity in canine leishmaniosis

Canine leishmaniosis (CanL) is caused by the parasite Leishmania infantum and is a systemic disease, which can present with variable clinical signs, and clinicopathological abnormalities. Clinical manifestations can range from subclinical infection to very severe systemic disease. Leishmaniosis is categorized as a neglected tropical disease and the complex immune responses associated with Leishmania species makes therapeutic treatments and vaccine development challenging for both dogs and humans. In this review, we summarize innate and adaptive immune responses associated with L. infantum infection in dogs, and we discuss the problems associated with the disease as well as potential solutions and the future direction of required research to help control the parasite.

Seizures as a Consequence of Hyperviscosity Syndrome in Two Dogs Naturally Infected with Leishmania infantum

Serum hyperviscosity syndrome (HVS) was documented in two dogs with canine leishmaniasis (CanL) and seizures as the major clinical complaint. In both cases, laboratory abnormalities included mild non-regenerative anemia, thrombocytopenia, hypoalbuminemia, hyperproteinemia with monoclonal gammopathy, and marked serum hyperviscosity. CanL was diagnosed using cytology in one case and indirect immunofluorescence assay and conventional polymerase chain reaction in the second. Specific therapy with meglumine antimoniate and allopurinol(c) led to short-term remission in both dogs and normalization of serum viscosity. Although dogs rarely develop HVS, it should be suspected if hyperproteinemia and monoclonal gammopathy are present. Since CanL manifests with a variety of clinical presentations, including seizures resulting from HVS-induced central nervous system hypoxia, it should also be considered as a differential diagnosis in animals with seizures as a primary presenting sign.

Pathology of dogs in Campo Grande, MS, Brazil naturally co-infected with Leishmania infantum and Ehrlichia canis

Different parasites that commonly occur concomitantly can influence one another, sometimes with unpredictable effects. We evaluated pathological aspects of dogs naturally co-infected with Leishmania infantum and Ehrlichia canis. The health status of the dogs was investigated based on histopathological, hematological and biochemical analyses of 21 animals infected solely with L. infantum and 22 dogs co- infected with L. infantum and E. canis. The skin of both groups showed chronic, predominantly lymphohistioplasmacytic inflammatory reaction. The plasmacytosis in the lymphoid tissues was likely related with the hypergammaglobulinemia detected in all the dogs. The disorganization of extracellular matrix found in the reticular dermis of the inguinal region and ear, characterized by the substitution of thick collagen fibers for thin fibers, was attributed to the degree of inflammatory reaction, irrespective of the presence of parasites. In addition, the histopathological analysis revealed that twice as many dogs in the co-infected group presented Leishmania amastigotes in the ear skin than those infected solely with Leishmania, increasing the possibility of becoming infected through sand fly vectors. Our findings highlight the fact that the health of dogs infected concomitantly with L. infantum and E. canis is severely compromised due to their high levels of total plasma protein, globulins, alkaline phosphatase and creatine kinase, and severe anemia.

An update on the diagnosis and treatment of canine leishmaniosis caused by Leishmania infantum (syn. L. chagasi)

Canine leishmaniosis caused by Leishmania infantum is still a common disease in endemic areas, such as the Mediterranean countries, and has progressively expanded into non-endemic areas like Central and Northern Europe. The aim of this article is to critically review current knowledge on the diagnosis and treatment of this disease. In dogs with typical clinical signs and clinicopathological abnormalities, diagnosis is relatively easy based on the exclusion of major differentials, the demonstration of the parasite (e.g., with lymph node and/or skin cytology) and the presence of Leishmania-specific immunoglobulin G antibodies (quantitative serology). In less typical cases, these criteria together with the exclusion of possible differentials and the demonstration of compatible histological lesions in affected organs and tissues form the basis for a sound diagnosis. In clinically healthy dogs, molecular techniques are the most sensitive means for detecting L. infantum infection. Treatment of canine leishmaniosis should follow clinical staging and is usually based on meglumine antimonate or miltefosine administration for a few weeks in combination with allopurinol for several months. However, allopurinol monotherapy may be used in very mild cases as well as in dogs with end stage kidney disease. Aminosidine administered once daily at a revised dosage shows some promise but additional controlled studies are needed. Close attention to published guidelines regarding treatment and follow-up is necessary to achieve the best possible therapeutic outcome.

Management of canine leishmaniosis in endemic SW European regions: a questionnaire-based multinational survey

Background

Canine leishmaniosis (CanL) caused by Leishmania infantum is a widespread endemic disease in SW Europe. This study was designed to determine how veterinarians clinically manage CanL in this region by analysing information collected in a questionnaire completed by local veterinarians working in clinics in France, Portugal, Greece, Spain, Italy and Slovenia.

Methods

Over the period 2004–2011, a questionnaire on CanL was sent to 12,546 small animal clinics located in the six countries surveyed. The questionnaire with 10 items comprising open and closed questions sought to obtain comparable data regarding the main clinical manifestations of CanL, the diagnostic methods used, the treatment regimens selected, recommended preventive measures and awareness of the important public health implications of CanL.

Results

The data collected reflect similarities in the clinical manifestations reported although there was some variation in the concurrent diseases described, and wide variation in the clinical management of CanL among the countries examined in terms of dosing regimens, therapeutic agents and the criteria used to diagnose CanL. Most veterinarians properly informed dog owners about the preventive measures available and about the zoonotic implications of CanL.

Conclusions

This survey describes the current situation in SW endemic countries in Europe regarding the clinical management of CanL. The data collected reveal a need to unify criteria from evidence-based medicine to determine and similarly apply the best diagnostic and treatment methods available for this disease in the different countries.

Pathologic mechanisms underlying the clinical findings in canine leishmaniasis due to Leishmania infantum/chagasi

In dogs with symptomatic or asymptomatic leishmaniasis, Leishmania infantum appears to induce a mixed Th1/Th2 immune response that in the sick dog may eventually result in tissue damage via different pathomechanisms, notably granulomatous inflammation (eg, nodular dermatitis, osteomyelitis), immune complex deposition (eg, glomerulonephritis), and/or autoantibody production (eg, polymyositis). This is a compensatory but detrimental mechanism generated mainly because of the insufficient killing capacity of macrophages against the parasite in the susceptible dog. Clinical disease is typically exemplified as exfoliative and/or ulcerative dermatitis, with or without nasodigital hyperkeratosis and onychogryphosis, glomerulonephritis, atrophic myositis of masticatory muscles, anterior uveitis, keratoconjunctivitis sicca, epistaxis, and/or polyarthritis, appearing alone or in various combinations. The pathogenesis of these clinical conditions has recently been highlighted, to a greater or lesser extent. The usually subclinical conditions expressed as chronic colitis, chronic hepatitis, vasculitis, myocarditis, osteomyelitis, orchiepididymitis, and meningoencephalomyelitis, though uncommon, are of pathologic importance from a differential point of view. The leading cause of death among canine leishmaniasis patients is chronic proteinuric nephritis that may progress to end-stage kidney disease, nephrotic syndrome, and/or systemic hypertension. However, even the asymptomatic proteinuria, when profuse, may be a serious problem because it predisposes to arterial thromboembolism and eventually contributes to the deterioration of the body condition.

Nasal, oral and ear swabs for canine visceral leishmaniasis diagnosis: new practical approaches for detection of Leishmania infantum DNA

Background

The aim of this study was to evaluate the potential use of nasal, oral, and ear swabs for molecular diagnosis of canine visceral leishmaniasis (CVL) in an endemic urban area in Brazil.

Methodology/Principal Findings

Sixty-two naturally infected and ten healthy dogs were enrolled in this study. Bone marrow aspirates, peripheral blood, skin biopsy, and conjunctival, nasal, oral, and ear swabs were collected. All samples, except blood, were submitted to conventional PCR (cPCR) and quantitative real time PCR (qPCR) to detect and quantify Leishmania infantum DNA, respectively. All dogs were submitted to thorough clinical analysis and were included based on a combination of serological (ELISA immunoassay and immunofluorescent antibody test) and parasitological methods. The cPCR positivity obtained from nasal swab samples was 87% (54/62), equivalent to those from other samples (P>0.05). Positive results were obtained for 79% (22/28) in oral swabs and 43% (12/28) in ear swab samples. A significant difference was observed between these data (P = 0.013), and the frequency of positive results from oral swab was equivalent to those from other samples (P>0.05). The use of ear swab samples for cPCR assays is promising because its result was equivalent to skin biopsy data (P>0.05). The qPCR data revealed that parasite loads in mucosal tissues were similar (P>0.05), but significantly lower than the parasite burden observed in bone marrow and skin samples (P<0.05).

Conclusions

Nasal and oral swab samples showed a high potential for the qualitative molecular diagnosis of CVL because their results were equivalent to those observed in samples collected invasively. Considering that mucosae swab collections are painless, noninvasive, fast and practical, the combination of these samples would be useful in massive screening of dogs. This work highlights the potential of practical approaches for molecular diagnosis of CVL and human leishmaniasis infections.

Visceral leishmaniasis (VL) is an important public health problem in different regions of the world. It presents high lethality in human cases without suitable treatment and is considered one of the most important disorders in dogs, the main domestic reservoir of the etiological agent of VL (Leishmania infantum). Most cases of VL in Latin America occur in Brazil, and control campaigns have not shown satisfactory results. The diagnosis of human and canine infection is critical for making decisions regarding surveillance and control policies. In this work, we propose a non-invasive collection method of mucosal and epithelial cells for the molecular diagnosis of canine VL by conventional polymerase chain reaction (cPCR) and for the estimation of parasite load by quantitative real time PCR (qPCR). We used nasal, oral, and ear swabs as practical, simple, painless and fast alternatives for collecting samples. These procedures are according to the need of more simplified methods for detecting L. infantum infection by using robust diagnostic techniques such as cPCR and qPCR. Additionally, potential applications for diagnosing human VL are highlighted.

Disseminated intravascular coagulation in a dog naturally infected by Leishmania (Leishmania) chagasi from Rio de Janeiro - Brazil

BACKGROUND

Disseminated intravascular coagulation (DIC) is an acquired disorder characterized by the activation of intravascular coagulation and excessive fibrin formation. It always occurs in association with other clinical conditions, including parasitic diseases. DIC has been described as a unusual complication in human and canine visceral leishmaniasis.

CASE PRESENTATION

DIC was found in a seven-year-old male mongrel dog naturally infected by Leishmania (Leishmania) chagasi. Haemostasis parameters demonstrated changes in primary and secondary haemostasis and fibrinolysis.

CONCLUSION

DIC is a unusual condition described in canine visceral leishmaniasis and it seems to be associated with several immunological and pathological mechanisms involved in the disease.

LeishVet guidelines for the practical management of canine leishmaniosis

The LeishVet group has formed recommendations designed primarily to help the veterinary clinician in the management of canine leishmaniosis. The complexity of this zoonotic infection and the wide range of its clinical manifestations, from inapparent infection to severe disease, make the management of canine leishmaniosis challenging. The recommendations were constructed by combining a comprehensive review of evidence-based studies, extensive clinical experience and critical consensus opinion discussions. The guidelines presented here in a short version with graphical topic displays suggest standardized and rational approaches to the diagnosis, treatment, follow-up, control and prevention of canine leishmaniosis. A staging system that divides the disease into four stages is aimed at assisting the clinician in determining the appropriate therapy, forecasting prognosis, and implementing follow-up steps required for the management of the leishmaniosis patient.

The immunopathology of canine vector-borne diseases

The canine vector-borne infectious diseases (CVBDs) are an emerging problem in veterinary medicine and the zoonotic potential of many of these agents is a significant consideration for human health. The successful diagnosis, treatment and prevention of these infections is dependent upon firm understanding of the underlying immunopathology of the diseases in which there are unique tripartite interactions between the microorganism, the vector and the host immune system. Although significant advances have been made in the areas of molecular speciation and the epidemiology of these infections and their vectors, basic knowledge of the pathology and immunology of the diseases has lagged behind. This review summarizes recent studies of the pathology and host immune response in the major CVBDs (leishmaniosis, babesiosis, ehrlichiosis, hepatozoonosis, anaplasmosis, bartonellosis and borreliosis). The ultimate application of such immunological investigation is the development of effective vaccines. The current commercially available vaccines for canine leishmaniosis, babesiosis and borreliosis are reviewed.

Secondary immune-mediated thrombocytopenia in dogs naturally infected by Leishmania infantum

Forty-four dogs naturally infected by Leishmania infantum were divided into two groups: 20 thrombocytopenic dogs with fewer than 150 x 10(9) platelets/l, and 24 non-thrombocytopenic dogs with more than 200 x 10(9) platelets/l. Ten clinically healthy dogs were used as controls. A haematological profile was obtained and the dogs' serum was used to assess the presence of platelet-binding IgM and IgG antibodies using a flow cytometry technique. Nineteen of the 20 thrombocytopenic dogs, and 13 of the 24 non-thrombocytopenic dogs had detectable levels of platelet-binding immunoglobulins, but none of the control dogs did so. The differences were significantly different for both IgM and IgG platelet-binding antibodies.

Directions for the diagnosis, clinical staging, treatment and prevention of canine leishmaniosis

Canine leishmaniosis (CanL) due to Leishmania infantum is a life threatening zoonotic disease with a wide distribution in four continents and importance also in non-endemic regions. The purpose of this report is to present a consensus of opinions on the diagnosis, treatment, prognosis and prevention of CanL in order to standardize the management of this infection. CanL is a disease in which infection does not equal clinical illness due to the high prevalence of subclinical infection among endemic canine populations. The most useful diagnostic approaches include serology by quantitative techniques and PCR. High antibody levels are associated with severe parasitism and disease and are diagnostic of clinical leishmaniosis. However, the presence of lower antibody levels is not necessarily indicative of disease and further work-up is necessary to confirm CanL by other diagnostic methods such as cytology, histopathology and PCR. We propose a system of four clinical stages, based on clinical signs, clinicopathological abnormalities and serological status. Suitable therapy and expected prognosis are presented for each of the stages. The combination of meglumine antimoniate and allopurinol constitutes the first line pharmaceutical protocol. However, although most dogs recover clinically after therapy, complete elimination of the parasite is usually not achieved and infected dogs may eventually relapse. Follow-up of treated dogs with blood counts, serum biochemistry, urinalysis, serology and PCR is essential for prevention of relapses. Protection against sand fly bites by topical insecticides is effective in reducing infection, and recent development of vaccines has indicated that prevention by vaccination is feasible.

Managing canine vector-borne diseases of zoonotic concern: part one

Canine vector-borne diseases (CVBDs) comprise a group of globally distributed and rapidly spreading illnesses that are caused by a range of pathogens transmitted by arthropods including ticks, fleas, mosquitoes and phlebotomine sandflies. In addition to their veterinary importance, some CVBD-causing pathogens are of major zoonotic concern. Recent studies using sophisticated and advanced methodologies and technologies have provided new insights into the epidemiology of many CVBDs. This review is the first of two articles and focuses on the zoonotic relevance of CVBDs, the significance of co-infection and the role of infected but clinically healthy dogs in spreading different pathogens among human and canine populations.